There is an ongoing need for effective, simple and inexpensive methods to inactivate enveloped and nonenveloped viruses in plasma and plasma-derived products. Pressure Cycling Technology (PCT) is an unique and innovative physical methodology that meets this requirement without concerns for potential protein damage associated with heat treatment or requirements for addition of possibly toxic or mutagenic chemicals. PCT achieves virus inactivation through application of repeated pulses of hyperbaric pressure to plasma or protein solutions. In initial studies, we have demonstrated that PCT can be used to inactivate three viruses that are potential contaminants of human plasma including HIV, herpesvirus and the highly resistant parvovirus and have identified PCT conditions that maintain greater than 75 percent of the functional integrity of factor VIII, a particularly labile plasma protein. We propose to continue efforts to optimize PCT in regard to pressure, temperature and cycling conditions so as to maximize virus inactivation with minimal loss of plasma protein function and to demonstrate that these PCT conditions apply to inactivation of a wide range of viruses. To establish the commercial potential of PCT-mediated virus inactivation, a broad spectrum of plasma proteins will be evaluated for retention of functional and structural integrity following PCT treatment. PROPOSED COMMERCIAL APPLICATION: Not Available